U.N. nuclear chief says 'urgent' for Iran to address concerns

VIENNA (Reuters) - The U.N. nuclear chief told Iran on Monday it was "essential and urgent" for it to address concerns about suspected atomic bomb research, signalling his hope that the new government in Tehran will stop stonewalling his inspectors.

Yukiya Amano was addressing a session of the U.N. agency's 35-nation board, the first since relative moderate Hassan Rouhani took office as Iranian president in early August, raising cautious optimism of progress in the nuclear dispute.